Good experience and good value. The host family is really kind and attentive. Even though it's in an old building and Bangkok can be hot and humid, my room and the attached bathroom was very clean, free of any dust, mould or smells.
However, make sure to check what floor your room is on, as it can be a long walk up - especially if you have luggage or back issues. I was on the fifth, and generally preferred that, as I felt the air would be cleaner higher up. But the first couple of days my back had been hurting, and it was a bit restrictive. Anyhow I ended up staying for week and a half. Overall quiet, but bring earplugs for the occasional motorbikes and one hawker with loudspeaker earlier in the morning - it stays pretty warm and I had to sleep with my balcony door open. Ken got me a second pedestal fan when I asked which was helpful!
A 12-15 minute walk from the bus and MRT, once again I personally preferred being away from the major streets and the fairly intense vehicular pollution of Bangkok, and once you get used to the walk it's no issue. There is a moto-taxi station by the bus/MRT that you have, although I, personally, was fine walking.
I plan to say again when in Bangkok!